I am having hard time figuring out what I am doing wrong here.
If I use a NBFM Receive block, it works well, I hear the NOAA transmission.
If I replace the NBFM Receiver with a quadrature demod, FM deemphasis, LP filter, then I just hear only noise.
I looked at the source code of the NBFM Receiver and it seems to be doing exactly that.
I must be missing something very trivial. Anybody has a hint, please?
Screenshot and .grc attached.
Thank you,
Ludovico
